(a) Field of the Invention
The present invention relates to an improvement in operating panel device in an electronic musical instrument.
(b) Description of the Prior Art
On the panel face of a keyboard electronic musical instrument in general, there are provided a number of operating knobs or buttons which are, for example, switches and volumes for setting the functions of the musical instrument such as automatic rhythm and autobass chord (called "ABC" briefly) and for setting tonal characteristics such as tone color, tone volume and effect separately for each keyboard or key range. Such operating knobs number about fifty (50) at least, and can amount to as many as two hundred (200) in a large-scale instrument. These many operating or manipulating knobs are disposed on the panel face in a plurality of groups, each group consisting of knobs belonging to a similar functional category. Because the knobs are provided not a few in number, the user of the instrument, especially the beginners, tends to consume much time to operate the knobs and gets confused.
With the aim to reduce the number of these manipulating knobs which are provided on the panel face, a proposal has been made to provide a group of operating knobs in common for several different modes (for example, Japanese Utility Model Preliminary Publication No. Sho 57-57496). In this prior art, however, a plurality of mode-changing switches are disposed on the panel face. Therefore, as the number of modes increases, the number of the mode-changing switches which are to be provided on the panel face naturally increases accordingly, and this, in turn, gives rise to the inconvenience that the easy operability of the instrument is hampered. In addition, the user of this instrument encounters a difficulty and becomes confused in catching the relationship between the respective knobs and the working functions for the respective modes which are to be selected by manipulating these knobs.